Falls are a major problem for many elderly people. Older people can often have reduced muscle power along with poorer coordination and balance, a combination that leaves them less able to correct the occasional stumbles we all have. And older people who fall are more likely to break bones, especially when there’s poor nutrition and diminished bone density.

Another contributory factor to falling that is attracting a lot of interest at present is the effect of poor vision. Try closing your eyes and standing in one place. Most people from middle-life onwards will feel unsteady doing this. Imagine what it’s like if you also have poor balance and you’re lacking in muscle power.

Bifocal spectacles can make an otherwise healthy person feel unsteady, for example when they look through the reading part of the lens when walking downstairs. Impairment from cataracts has an even greater effect. This condition is common with increasing age, so a recent study looking at how corrective surgery can prevent falls is important.

Researchers in the United States* searched their Medicare database in order to compare the number of bone fractures in 400,000 people who had cataracts removed surgically with 300,000 people who hadn’t been operated on. During a year of follow-up, 1.3% of the total number suffered a hip fracture and 5.4% sustained fractures of any bone. But what they found was that – after making adjustments for factors like other illnesses that might have made surgery impractical – those who had received cataract surgery had a 16% lower risk of hip fracture and a 4% lower risk of any fracture. In those with the greatest impairment from cataracts, hip fracture was 23% lower after surgery. Smaller studies from the UK showed similar benefits.

This study shows that the importance of removing cataracts and restoring vision goes beyond simply improving the quality of life through being able to see better. Broken bones can be debilitating to even the most active of people, and can be a major burden for the individual and their relatives and carers. Injuries to the wrist bones impair eating and toileting; and injuries to major bones and joints, such as the hip, often need admission to hospital and a major operation, which can be poorly tolerated by older people.

Exercise is seen as important for people who have type 2 diabetes and for those who may not have it yet but are heading in that direction. These people are often overweight, but it now seems that physical activity is doing more than simply helping them burn calories.

Recent studies have shown that resistance training – physical activity such as weight training, where you exercise your muscles against a resistance – brings greater benefit than expected in the fight against diabetes. This type of exercise burns far fewer calories than aerobic activities such as running, swimming, cycling and so on. That suggests the benefit must come in some other way.

Researchers have now analysed the activities of 32,000 US men over an 18 year period*. Those who engaged for more than 150 minutes per week in either aerobic or weight training had a 54% or 34% lower risk respectively of developing diabetes. Those who did both types of exercise had an even greater reduction of 59%.

These findings are interesting in several respects. First, some people prefer resistance training to aerobic activities and it is good to know they are deriving worthwhile benefit. Second, it’s valuable to have further confirmation that combining different types of exercise brings even greater benefits. And then there’s the intriguing scientific question of what process is actually bringing the benefit.

It seems that increasing muscle mass and power alters sensitivity to insulin, the substance that controls the level of glucose in your blood. Aerobic exercise changes how oxygen is handled and the activity of the enzymes that metabolise fat, whereas resistance exercise changes muscle type and the ability to metabolise glucose. That might be why these different types of activity both have benefits – and why combining them is even better.

If you aren’t able to manage the full amount of exercise recommended, don’t despair. A further finding is that lower levels of activity still bring some benefit, although not as much.